Bio 172 Exam 1 University of Michigan

Properties of Life

1) Order

2) Energy Utilization

3) Regulation or Homeostasis

4) Response to Environment

5) Reproduction

6) Evolution and Adaption

7) Growth and Development

Cell

lowest level in hierarchy of biological organization

stores & transmits information

Theory of Evolution

All species are related by decent from a common ancestor

Natural Selection

Individuals with heritable traits must survive and reproduce better than individuals with other traits

Tree of Life

A diagram depicting the genealogical relationships of all living organisms on Earth, with a single ancestral species at the base.

Archea

Domain of prokaryotic organisms that are biochemically and genetically distinct from bacteria.

Eukaryotes

Cells that contain nuclei

Prokaryotes

Cells that do not contain nuclei

Extremophiles

A prokaryote that lives in an extreme environment.

Thermophile

A group of Archae that thrive in very hot places.

Acidophiles

Acid Lover Archaea

Halophile

"salt-loving" archaea that live in environments that have very high salt concentrations

Cell Theory

1) Cells are structural units of life

2) Cells are the functional unit of life

3) All cells are fundamentally similar. Specific cell functions vary

4) All cells come from pre-existing cells

Fact

Has been repeatedly confirmed

Hypothesis

Testable statement

Law

Descriptive Generalization

Theory

explanation that is well-substantiated and can incorporate facts, laws, inferences, and tested hypotheses

Scientific Method

A series of steps followed to solve problems including collecting data, formulating a hypothesis, testing the hypothesis, and stating conclusions.

Protons

Have a positive charge

Atomic number

Found in nucleus

Contributes to atomic mass

Neutrons

Has a neutral charge

Found in nucleus

Contributes to atomic mass

Electron

Negative charge

Found in clouds/orbitals

Mass number

the sum of the number of neutrons and protons in an atomic nucleus

Valence

The electrons in the outermost shell (main energy level) of an atom; these are the electrons involved in forming bonds.

Covalent bond

A chemical bond that involves sharing a pair of electrons between atoms in a molecule

Nonpolar covalent bond

A type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity.

Polar covalent bond

A covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive.

Hydrogen Bond

A type of weak chemical bond formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule.

Ionic Bond

A chemical bond resulting from the attraction between oppositely charged ions.

Cation

Positive Ion

Anion

Negative Ion

Van der Waals

A slight attraction that develops between the oppositely charged regions of nearby molecules.

Cohesion

Attraction between molecules of the same substance

Adhesion

An attraction between molecules of different substances

Liquid

No crystal lattice forms in this form of H2O

Ice

This form of H2O is an excellent insulator

Polar molecules/Ions

Dissolve readily in H2O

Nonpolar molecules

Do not dissolve readily in H2O

Observation

Act of viewing the world around us

Experimentation

Disciplined and controlled way of asking and answering questions about the world in an unbiased manner

1st law of thermodynamics

The principle of conservation of energy. Energy can be transferred and transformed, but it cannot be created or destroyed.

2nd law of thermodynamics

Every energy transfer or transformation increases the entropy of the universe.

DNA

A double-stranded, helical nucleic acid molecule capable of replicating and determining the inherited structure of a cell's proteins.

Easily replicated

RNA

A single-stranded nucleic acid that passes along genetic messages

Transcription

(genetics) the organic process whereby the DNA sequence in a gene is copied into mRNA

Translation

(genetics) the process whereby genetic information coded in messenger RNA directs the formation of a specific protein at a ribosome in the cytoplasm

Central Dogma

DNA -> RNA -> Protein

gene

A segment of DNA on a chromosome that codes for a specific trait

Mutation

(genetics) any event that changes genetic structure

plasma membrane

A selectively-permeable phospholipid bilayer forming the boundary of the cells

Separates living/nonliving material

Nucleus

houses DNA

large & highly organized

structure: surrounded by a double-membrane nuclear envelope

function: information storage & processing

contains chromosomes

where RNA transcription occurs

Cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended

ATP

(adenosine triphosphate) main energy source that cells use for most of their work

metabolism

All of the chemical reactions that cells use to convert energy from one form to another

virus

genetic material in need of a cell.

"Hijacks" cells

Evolution

change over time

environmental variation

due to differences in the environment

genetic variation

differences in the genes that are transmitted from parents to their offspring

Ecology

the study of how organisms interact with one another and with their physical environment in nature

Atom

fundamental unit of matter

Molecules

Chemicals that result from atoms linking together

Chemical bonds

Forces that hold atoms or ions together in a compound

Water

_____ is a polar molecule

Structure of an amino acid

carbon atom (Alpha C) attached to a carboxyl group, an amino group, H, and a side chain (R group)

R group

determines the properties of each amino acid

nucleotide

A subunit of nucleic acid formed from a simple sugar, a phosphate group, and a nitrogenous base.

Pyrimidines

Thymine

Cytosine

Uracil

Purines

adenine

guanine

energy

the capacity to do work

# of amino acids

20

hydrophilic

interacts with water

hydrophobic

does not interact with water

polypeptide

A polymer (chain) of many amino acids linked together by peptide bonds.

peptide bond

bond formed between amino acids in a polypeptide

condensation reaction

reaction that produces H2O

peptide bonds are this type of reaction

primary structure

linear sequence of amino acids held together by covalent (peptide) bonds between amino acids

Alpha Carbon

Has four groups bonded to it; R side chain, amino group, carboxyl group, and hydrogen , refers to the first carbon that attaches to a functional group

secondary structure

interactions between atoms in the backbone

H bonds between the carboxyl group of 1 amino acid & the amino group of another form this structure

alpha helices

coiled secondary structure

beta pleated sheets

folded secondary structure

Tertiary structure

overall 3D shape of polypeptide

held together by interactions between R groups

Determinants of protein structure

cell environment

temperature

pH

salts

Quaternary Structure

the shape resulting from the association of two or more polypeptide subunits.

denaturization

loss of protein conformation

promoted by heat, pH change, chemicals

chaperones

Assist in proper folding and transport of polypeptides

renaturization

The process of a protein returning to its original configuration and function.

potential energy

stored energy

kinetic energy

energy of motion

High free energy

less stable

more concentrated

more ordered

greater work capacity

less favorable

Low free energy

more stable

less concentrated

less ordered

less work capacity

more favorable

diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration. From area of high free energy to low free energy

Energy releasing reactions

Exergonic

Exothermic

Spontaneous

Energy consuming reactions

Endergonic

Endothermic

Not spontaneous

Gibbs free energy

G=H-TS

H= total amount of energy

T=Temperature

S= change in entrophy

entrophy

measure of the disorder or randomness of the particles that make of a system (measurement of movement of particles in a spontaneous reaction)

exergonic

reactants have higher energy than product

spontaneous

energy is released

g<0

Endergonic

reactants have lower energy than products

non spontaneous

energy is required/consumed

g>0

Activation energy

energy required for reactants to reach the transition state

can be overcome by head or catalyst

transition state

An unstable grouping of atoms that exists momentarily in the course of a reaction, when a system is highest in energy.

catalyst

(chemistry) a substance that initiates or accelerates a chemical reaction without itself being affected

does not change the amount of energy released

does not change equilibrium constant

does lower the energy of activation

does raise the rate of reaction

substrates

- the molecule upon which an enzyme acts